If you need more than 4 USB ports to share between your two devices, you can pick up a self-powered USB hub. I ended up going with the TP-LINK USB 3.0 7-Port Hub (TL-UH700) and it works great. I can now share 7 devices at a time between my two machines with the UGREEN sharing switch. One thing to note though is that for whatever reason my Keyboard (Ducky Shine 5) did not switch properly when plugged into the USB hub so that one I still directly connect to the UGREEN switcher. Overall, my setup works great now and I can switch between my Mac/PC with a single button click. Highly recommend this device!